From owner-freebsd-alpha@FreeBSD.ORG  Wed Apr 16 05:50:06 2003
Return-Path: <owner-freebsd-alpha@FreeBSD.ORG>
Delivered-To: freebsd-alpha@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 3D64B37B401
	for <freebsd-alpha@freebsd.org>; Wed, 16 Apr 2003 05:50:06 -0700 (PDT)
Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 6D02343FDD
	for <freebsd-alpha@freebsd.org>; Wed, 16 Apr 2003 05:50:05 -0700 (PDT)
	(envelope-from gallatin@cs.duke.edu)
Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu
	[152.3.145.30])
	by duke.cs.duke.edu (8.12.9/8.12.9) with ESMTP id h3GCnxMS025819
	(version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO);
	Wed, 16 Apr 2003 08:50:02 -0400 (EDT)
Received: (from gallatin@localhost)
	by grasshopper.cs.duke.edu (8.11.6/8.9.1) id h3GCnsX58195;
	Wed, 16 Apr 2003 08:49:54 -0400 (EDT)
	(envelope-from gallatin@cs.duke.edu)
From: Andrew Gallatin <gallatin@cs.duke.edu>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Message-ID: <16029.20850.720877.563791@grasshopper.cs.duke.edu>
Date: Wed, 16 Apr 2003 08:49:54 -0400 (EDT)
To: Jarkko Santala <jake@iki.fi>
In-Reply-To: <20030416122206.S316@trillian.santala.org>
References: <Pine.OSF.4.33.0304151146380.1028-100000@poptart.bithose.com>
	<20030416122206.S316@trillian.santala.org>
X-Mailer: VM 6.75 under 21.1 (patch 12) "Channel Islands" XEmacs Lucid
cc: freebsd-alpha@freebsd.org
Subject: Re: problem with UDMA mode on XP1000
X-BeenThere: freebsd-alpha@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Porting FreeBSD to the Alpha <freebsd-alpha.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-alpha>,
	<mailto:freebsd-alpha-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-alpha>
List-Post: <mailto:freebsd-alpha@freebsd.org>
List-Help: <mailto:freebsd-alpha-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-alpha>,
	<mailto:freebsd-alpha-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 16 Apr 2003 12:50:06 -0000


Jarkko Santala writes:
 > On Tue, 15 Apr 2003, Jameel Akari wrote:
 > 
 > > 	I had the same sort of problem in an Alpha PC164, but in the end
 > > the onboard IDE was so terrible and Tru64 refused to run a hard disk on
 > > it, so I bought an ISP1040 and went SCSI, and it's been solid.
 > 
 > Well, I don't think it's that terrible:
 > 
 > dd if=/dev/zero of=foo bs=1m count=100:
 > ad0: 104857600 bytes transferred in 6.863760 secs (15276991 bytes/sec)
 > da0: 104857600 bytes transferred in 8.200968 secs (12786003 bytes/sec)
 > 
 > atapci0: <CMD 646 ATA controller> port 0x10180-0x1018f irq 5 at device 11.0 on pci0
 > ad0: 117246MB <Maxtor 4G120J6> [238216/16/63] at ata0-master WDMA2

FWIW, WDMA2 is not safe as there is no CRC checking.  I've seen
corrupted (random, infrequent single bit errors) files when running a
PC164LX with an ata drive in WDMA2 mode.  The higher modes (UDMA33 ..)
get you CRC checking.  As soon as we noticed the corruption, we moved
the box to SCSI.



Drew